Pulmonary alveolar proteinosis (PAP) is a lung disease of unknown etiology in which excessive quantities of a viscous, proteinaceous material fill the alveoli and respiratory bronchioles. In addition to various lipids, the secretions in PAP contain significant amounts of a number of glycoproteins. The objectives of the current proposal are to isolate and purify the major sialic acid-rich glycoproteins occurring in this disease using primarily column chromatographic procedures. The purified glycoproteins will be subjected to extensive chemical, physical and structural analysis with particular emphasis on their oligosaccharide side chains. Antibodies directed against these PAP glycoproteins will be used to investigate their site of synthesis or source. The structural and chemical relationship of these glycoproteins to those occurring in normal human lung secretions will be investigated. These studies may provide clues to etiology and molecular basis of PAP and may lead to improved therapeutic and diagnostic procedures.